Power storage device

Abstract

To provide a power storage device which suppresses damage of a joint part between a detection line and a terminal.SOLUTION: A power storage device includes: a power storage element 21 having terminals 221 and 222; detection lines 361 to 365 which are joined to the terminals and detect the state of the power storage element; and a fixing member 40 for superposing and fixing the terminals and the detection lines.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to an electricity storage device. [Background technology]

[0002] Patent Document 1 discloses an electricity storage system in which a housing contains an electricity storage unit formed by assembling a plurality of capacitor cells on a frame. In this electricity storage system, a distribution cable is connected to a collector electrode connector connected to the collector electrode of the capacitor cell. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-110035 Summary of the Invention [Problem to be solved by the invention]

[0004] Here, if the electricity storage system vibrates, the vibration may cause damage to the joint between the distribution cable and the collector electrode connector.

[0005] The present invention was made by the inventors of the present application by focusing on the above-mentioned problem, and has an object to suppress damage to the joint between the detection line and the terminal. [Means for solving the problem]

[0006] An energy storage device according to one aspect of the present invention includes an energy storage element having a terminal, a detection wire joined to the terminal for detecting the state of the energy storage element, and a fixing member for overlapping and fixing the terminal and the detection wire. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide an electricity storage device that can suppress damage to the joint between the detection line and the terminal. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view showing the appearance of a power storage device according to an embodiment. [Figure 2] FIG. 2 is an exploded perspective view showing each component of the electricity storage device according to the embodiment. [Figure 3] FIG. 3 is a perspective view showing a plurality of energy storage elements according to the embodiment in a separated state. [Figure 4] FIG. 4 is a plan view showing the electricity storage unit according to the embodiment. [Figure 5] FIG. 5 is a cross-sectional view showing a fixing member according to the embodiment. [Figure 6] FIG. 6 is a plan view showing an electricity storage unit according to the first modification. [Figure 7] FIG. 7 is a plan view showing an electricity storage unit according to the second modification. [Figure 8] FIG. 8 is a plan view showing an electricity storage unit according to the third modification. [Figure 9] FIG. 9 is a plan view showing an electricity storage unit according to the fourth modification. DETAILED DESCRIPTION OF THE INVENTION

[0009] (1) An energy storage device according to one aspect of the present invention includes an energy storage element having a terminal, a detection wire joined to the terminal for detecting the state of the energy storage element, and a fixing member for overlapping and fixing the terminal and the detection wire.

[0010] According to the energy storage device described in (1) above, the terminals and the detection wires are fixed with a fixing member, so that even if the terminals vibrate due to vibration of the energy storage element, the detection wires follow the vibration. Furthermore, because the terminals and the detection wires are overlapped and fixed with a fixing member, the terminals and the detection wires can be stably fixed. As a result, loads are less likely to be applied to the joints between the terminals and the detection wires, and damage to the joints can be suppressed.

[0011] (2) The power storage device described in (1) above may further include a detection line holding member that holds the detection line, and the fixing member may fix the detection line and the detection line holding member.

[0012] According to the power storage device described above in (2), the detection wire is fixed to the detection wire holding member by the fixing member, so that the detection wire can be held more stably. Therefore, the load on the joint between the terminal and the detection wire can be further reduced, and damage to the joint can be further reduced.

[0013] (3) The energy storage device according to (1) or (2) above may further include a holding member that holds the energy storage element, and the fixing member may be fixed to the holding member.

[0014] According to the energy storage device described in (3) above, since the fixing member is fixed to the holding member, the fixing member can easily follow vibrations of the energy storage element and the holding member, which can suppress displacement of the fixing member due to vibrations and therefore enable the terminal and the detection line to be stably fixed.

[0015] (4) In the storage device described in (3) above, a detection line holding member may be provided to hold the detection line, the fixing member may fix the detection line and the detection line holding member, and the holding member may be provided continuously with the detection line holding member.

[0016] According to the energy storage device described in (4) above, since the holding member includes the detection line holding member continuously, the fixing member can easily follow vibrations of the energy storage element, the holding member, and the detection line holding member. This further reduces positional deviation of the fixing member caused by vibrations, thereby enabling the terminal and the detection line to be fixed more stably.

[0017] (5) In any one of the above-described energy storage devices (1) to (4), the fixing member may be an adhesive tape, the adhesive tape may include a first base material layer and a second base material layer that is positioned farther from the terminal and the detection line than the first base material layer, the surface resistance of the first base material layer may be higher than the surface resistance of the second base material layer, and the tensile strength of the second base material layer may be higher than the tensile strength of the first base material layer.

[0018] According to the electricity storage device described in (5) above, since the fixing member is an adhesive tape, the detection line can be fixed to the bonding object with a simple configuration. Furthermore, since the surface resistance of the first base material layer arranged in a position close to the bonding object is higher than the surface resistance of the second base material layer, the insulation performance of the electricity storage device can be reliably improved. In addition, since the tensile strength of the second base material layer arranged in a position far from the bonding object is higher than the tensile strength of the first base material layer, the strength of the electricity storage device can be reliably improved even in a position far from the bonding object where displacement during vibration becomes large.

[0019] (Embodiment) Hereinafter, with reference to the drawings, a description will be given of an energy storage device according to an embodiment of the present invention (including modifications thereof). Note that the embodiments described below all show comprehensive or specific examples. The numerical values, shapes, materials, components, component placement positions and connection forms shown in the following embodiments are examples and are not intended to limit the present invention. In each drawing, dimensions and the like are not strictly illustrated. In each drawing, the same reference numerals are used for identical or similar components. The names of the components (each component) in this embodiment are those used in this embodiment and may differ from the names of the components (each component) in the background art.

[0020] In the following description and drawings, the X-axis direction is defined as the arrangement direction of the exterior body and exterior cover in the exterior body of the energy storage device, or the arrangement direction of multiple energy storage elements included in the energy storage device. The Y-axis direction is defined as the protruding direction of each lead terminal of an energy storage element. The Z-axis direction is defined as the arrangement direction of a pair of lead terminals included in an energy storage element, or the up-down direction. The X-axis direction, Y-axis direction, and Z-axis direction intersect with each other (orthogonal in the following embodiments and their modifications). Note that depending on the usage mode, the Z-axis direction may not be the up-down direction. However, for convenience of explanation, the Z-axis direction will be described as the up-down direction below. In the following description, the positive X-axis direction refers to the direction of the arrow on the X-axis, and the negative X-axis direction refers to the opposite side of the positive X-axis direction. The same applies to the Y-axis direction and the Z-axis direction. Furthermore, expressions indicating relative directions or attitudes, such as parallel and perpendicular, may also include cases where the directions or attitudes are not strictly those. "Two directions are perpendicular" does not only mean that the two directions are completely perpendicular, but also that they are substantially perpendicular, that is, that there is a difference of a few percent. In the following explanation, when the term "insulation" is used, it means "electrical insulation." An insulating material has a volume resistivity of 1×10 6 Ωm or more, more preferably 1×10 7 Ωm or more, more preferably 1×10 10 It is preferable that the material be made of a material with a resistance of Ωm or more.

[0021] [General explanation of the power storage device] First, an overall description of a power storage device 1 according to an embodiment will be given with reference to Figures 1 and 2. Figure 1 is a perspective view showing the appearance of the power storage device 1 according to an embodiment. Figure 2 is an exploded perspective view showing each component of the power storage device 1 according to an embodiment.

[0022] The power storage device 1 is a device capable of charging with electricity from an external source and discharging electricity to the outside, and in this embodiment, has a rectangular parallelepiped shape. A rectangular parallelepiped is a hexahedron with all faces formed of rectangles or squares. The power storage device 1 is a battery module (battery assembly) used for power storage, power supply, etc. Specifically, the power storage device 1 is used as a battery for driving or starting the engine of a moving object such as an automobile, motorcycle, personal watercraft, ship, snowmobile, agricultural machinery, construction machinery, automatic guided vehicle (AGV), or electric railway vehicle. Examples of the automobile include an electric vehicle (EV), a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), and a fossil fuel (gasoline, diesel, liquefied natural gas, etc.) vehicle. Examples of the electric railway vehicle include a train, a monorail, a linear motor car, and a hybrid train equipped with both a diesel engine and an electric motor. The power storage device 1 may be used as a stationary battery for home or business use.

[0023] 1 and 2, the energy storage device 1 includes an energy storage unit 20 and an exterior body 10 that houses the energy storage unit 20. The exterior body 10 includes an exterior body main body 11 that houses the energy storage unit 20, and an exterior body lid body 12 that covers the exterior body main body 11.

[0024] The exterior body 10 is a rectangular (box-shaped) container (module case) that constitutes the exterior body of the energy storage device 1. In other words, the exterior body 10 is a member that fixes the energy storage unit 20 and the like in predetermined positions and protects these elements from impacts and the like.

[0025] The exterior body main body 11 is a rectangular cylindrical member with a bottom that is open in the positive direction of the X axis, and the open portion is an opening 111. The opening 111 has a quadrangular shape in a plan view (as viewed in the X axis direction). In addition to the power storage unit 20, the opening 111 of the exterior body main body 11 accommodates a plurality of bus bars (not shown) and fuses (not shown) held by the power storage unit 20.

[0026] The exterior body lid 12 is a member that closes the opening 111 of the exterior body main body 11, and is joined to the exterior body main body 11 in a state in which the opening 111 of the exterior body main body 11 is closed from the positive direction of the X axis. A circuit board 35 is disposed outside the opening 111 at a position corresponding to the exterior body lid 12. In other words, the circuit board 35 is housed between the exterior body main body 11 and the exterior body lid 12. The exterior body lid 12 has a pair of external terminals 81 (positive and negative). The external terminals 81 are electrically connected to the multiple energy storage elements 21 included in the energy storage unit 20 via the bus bars, fuses, and circuit board 35. The energy storage device 1 charges with electricity from the outside and discharges electricity to the outside via the external terminals 81. The external terminals 81 are formed of a conductive member made of a metal such as copper, a copper alloy, aluminum, an aluminum alloy, or nickel, or a combination thereof, or a conductive member other than a metal.

[0027] Here, each bus bar is a plate-like member that electrically connects external terminals 81 and energy storage elements 21. Each bus bar is formed of a conductive member made of metal such as copper, copper alloy, aluminum, aluminum alloy, or nickel, or a combination thereof, or a conductive member other than metal.

[0028] The fuse is a component that protects circuit board 35, power storage elements 21, etc. from a current greater than the rated current. When a current greater than the rated current flows, the fuse melts to interrupt the flow of current.

[0029] The circuit board 35 has multiple electrical components (not shown), and these multiple electrical components form a detection circuit that detects the state (temperature, voltage, current, etc.) of each storage element 21, and a control circuit that controls charging and discharging.

[0030] The exterior body 11 and exterior body lid 12 of the exterior body 10 are formed from insulating materials such as polycarbonate (PC), polypropylene (PP), polyethylene (PE), polystyrene (PS), polyphenylene sulfide resin (PPS), polyphenylene ether (PPE (including modified PPE)), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyether ether ketone (PEEK), tetrafluoroethylene-perfluoroalkyl vinyl ether (PFA), polytetrafluoroethylene (PTFE), polyethersulfone (PES), polyamide (PA), ABS resin, or composite materials thereof, or from metals or the like with an insulating coating. This prevents the energy storage elements 21 and the like from coming into contact with external metal members or the like. Note that the exterior body 10 may be formed from a conductive material such as metal as long as the electrical insulation of the energy storage elements 21 and the like is maintained. Exterior body 11 and exterior body lid 12 may be made of the same material or different materials.

[0031] [Energy storage unit] The energy storage unit 20 includes a plurality of energy storage elements 21, a holding member 22, and a fixing member 40 (see FIG. 4).

[0032] The energy storage element 21 is a secondary battery (single cell) that can charge and discharge electricity, and more specifically, is a non-aqueous electrolyte secondary battery such as a lithium ion secondary battery. In this embodiment, the energy storage element 21 is a pouch-type energy storage element having a flat shape, and a plurality of (four in this embodiment) pouch-type energy storage elements 21 are arranged side by side in the X-axis direction. The energy storage element 21 is not limited to a pouch-type energy storage element, and may be an energy storage element having a flat rectangular parallelepiped (square shape), a polygonal prism shape other than a rectangular parallelepiped, a cylindrical shape, an elongated cylindrical shape, or an elliptical cylindrical shape, and the size and shape thereof are not limited. The number of energy storage elements 21 to be arranged is also not particularly limited. The energy storage element 21 is not limited to a non-aqueous electrolyte secondary battery, and may be a secondary battery other than a non-aqueous electrolyte secondary battery, a capacitor, or a battery using a solid electrolyte. The energy storage element 21 may be a primary battery instead of a secondary battery. The plurality of energy storage elements 21 are arranged in the X-axis direction, and adjacent energy storage elements 21 may or may not be joined together with an adhesive or double-sided tape. Details of energy storage elements 21 will be described later.

[0033] The holding member 22 is a member that holds the multiple energy storage elements 21. The holding member 22 includes a first holding member 23 and a second holding member 24 that holds the multiple energy storage elements 21 together with the first holding member 23. Specifically, the first holding member 23 is arranged in the negative X-axis direction of the multiple energy storage elements 21 and is bonded to an energy storage element 21 that is arranged at an end of the multiple energy storage elements 21 in the negative X-axis direction with an adhesive or double-sided tape. The second holding member 24 is arranged in the positive X-axis direction of the multiple energy storage elements 21 and is bonded to an energy storage element 21 that is arranged at an end of the multiple energy storage elements 21 in the positive X-axis direction with an adhesive or double-sided tape. As a result, the first holding member 23 and the second holding member 24 hold the multiple energy storage elements 21 while sandwiching them in the X-axis direction. Note that at least one of the first holding member 23 and the second holding member 24 does not have to be bonded to the energy storage element 21. In other words, both first holding member 23 and second holding member 24 do not have to be joined to energy storage element 21.

[0034] The first holding member 23 and the second holding member 24 are formed from an insulating material such as polycarbonate (PC), polypropylene (PP), polyethylene (PE), polystyrene (PS), polyphenylene sulfide resin (PPS), polyphenylene ether (PPE (including modified PPE)), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyether ether ketone (PEEK), tetrafluoroethylene-perfluoroalkyl vinyl ether (PFA), polytetrafluoroethylene (PTFE), polyethersulfone (PES), polyamide (PA), ABS resin, or a composite material thereof, or from a metal or the like with an insulating coating. As a result, the first holding member 23 and the second holding member 24 prevent the plurality of energy storage elements 21 from becoming electrically conductive with external conductive members such as metal members. However, if such conduction is not necessary, the first holding member 23 and the second holding member 24 may be formed from an electrically conductive member such as a metal. The first holding member 23 and the second holding member 24 may be made of the same material or different materials.

[0035] First holding member 23 includes flat plate portion 25 that overlaps energy storage element 21 at the end facing the negative X-axis direction, and bus bar support portion 26 that extends in the positive X-axis direction from flat plate portion 25. Small walls 251 that protrude in the positive X-axis direction are provided around the entire periphery of flat plate portion 25 at the edge of flat plate portion 25. Bus bar support portion 26 extends in the positive X-axis direction from corners of flat plate portion 25 facing the negative Y-axis and negative Z-axis directions, and supports a bus bar (not shown).

[0036] The second holding member 24 includes a board support portion 27 that overlaps the energy storage element 21 at its end in the positive direction of the X-axis. The board support portion 27 supports a circuit board 35 and includes a surrounding wall 29 that surrounds the circuit board 35. The board support portion 27 supports a bus bar and a fuse (not shown). At the end of the second holding member 24 in the negative direction of the Y-axis, a detection line holding member 28 extends in the negative direction of the X-axis. The second holding member 24 includes the detection line holding members 28 continuously. The detection line holding member 28 is a portion that holds a plurality of detection lines 36 connected to the circuit board 35 in order to detect the state (temperature, voltage, current, etc.) of each energy storage element 21.

[0037] [Energy storage element] Next, the energy storage elements 21 will be described in detail. Fig. 3 is a perspective view showing a plurality of energy storage elements 21 according to the embodiment separated from one another. The plurality of energy storage elements 21 have the same basic structure, but their outer shapes are partially different. Specifically, the odd-numbered energy storage elements 21 counted from the negative X-axis direction have partially different outer shapes from the even-numbered energy storage elements 21 counted from the negative X-axis direction. In other words, the odd-numbered energy storage elements 21 have the same outer shape, and the even-numbered energy storage elements 21 have the same outer shape.

[0038] First, a description will be given of the basic structure of the energy storage element 21. The energy storage element 21 includes an exterior film 210 and a pair of lead terminals 220 (positive and negative electrodes), and an electrode body 211 and an electrolyte (non-aqueous electrolyte: not shown) are housed inside the exterior film 210. There are no particular restrictions on the type of electrolyte as long as it does not impair the performance of the energy storage element 21, and any known material can be used as appropriate.

[0039] The exterior film 210 is a sheet-like exterior body made of laminate film, and houses the electrode assembly 211, an electrolyte solution, etc., sealed under reduced pressure. The exterior film 210 is configured by stacking two rectangular laminate films in the X-axis direction. The two laminate films are joined (sealed) by heat welding or the like, sandwiching a pair of lead terminals 220 between them. The two laminate films are joined (sealed) by heat welding or the like at locations that do not correspond to the pair of lead terminals 220. The laminate film is a flexible film made of multiple layers including a metal layer such as aluminum and a resin layer such as polypropylene (PP) or polyethylene (PE), and the resin layer is disposed at the welded locations (sealed portions). The exterior film 210 may also be configured by forming a single laminate film into a bag shape and joining the ends of the laminate film together by heat welding.

[0040] The lead terminals 220 are conductive plate-like members (lead plates) electrically connected to the electrode body 211, and are disposed so as to penetrate the exterior film 210 and be exposed therefrom. The lead terminals 220 are an example of terminals protruding from one end of the energy storage element 21. In this embodiment, a pair of lead terminals 220 aligned in the Z-axis direction are disposed so as to protrude in the negative Y-axis direction from an end of the exterior film 210 in the negative Y-axis direction. Specifically, the positive electrode lead terminal 220 is a lead terminal electrically connected to the positive electrode plate of the electrode body 211, and the negative electrode lead terminal 220 is a lead terminal electrically connected to the negative electrode plate of the electrode body 211. In other words, the lead terminals 220 are metal electrode terminals for guiding electricity stored in the electrode body 211 to the external space of the energy storage element 21 and for introducing electricity into the internal space of the energy storage element 21 in order to store electricity in the electrode body 211. The lead terminals 220 are formed of aluminum, an aluminum alloy, copper, a copper alloy, or the like.

[0041] The electrode body 211 is an electricity storage element (power generation element) formed by stacking a positive electrode plate, a negative electrode plate, and a separator. The positive electrode plate is a current collector foil made of a metal such as aluminum or an aluminum alloy, on which a positive electrode active material layer is formed. The negative electrode plate is a current collector foil made of a metal such as copper or a copper alloy, on which a negative electrode active material layer is formed. As the active material used in the positive electrode active material layer and the negative electrode active material layer, any known material can be used as long as it is capable of absorbing and releasing charge transport ions. The separator can be a microporous sheet or nonwoven fabric made of resin. In this embodiment, the electrode body 211 is formed by stacking electrode plates (positive electrode plate and negative electrode plate) in the X-axis direction. The electrode body 211 may be an electrode body of any shape, such as a wound type electrode body formed by winding electrode plates (positive electrode plates and negative electrode plates), a laminated type (stack type) electrode body formed by stacking multiple flat electrode plates, or a bellows type electrode body in which electrode plates are folded in a bellows shape.

[0042] Next, the difference between odd-numbered storage elements 21 and even-numbered storage elements 21 will be described.

[0043] The odd-numbered energy storage elements 21 and the even-numbered energy storage elements 21 share a common configuration: the exterior film 210 includes a main film 212 overlapping the electrode body 211, and a frame portion 213 protruding outward from the entire periphery of the main film 212. The main film 212 overlaps each side of the electrode body 211. The frame portion 213 is a sheet-like portion and is formed into a rectangular shape when viewed from the X-axis direction. A pair of lead terminals 220 protrude in the negative Y-axis direction from a first side 214 of the frame portion 213, which is the edge in the negative Y-axis direction, and are bent in the X-axis direction so as to be in opposite directions. Each lead terminal 220 is bent near the first side 214 of the exterior film 210. A portion of each lead terminal 220 that is farther from the main film 212 relative to the bending position is referred to as a tip portion 230.

[0044] Here, in odd-numbered energy storage elements 21, tip portions 231 of lead terminals 221 facing the positive Z-axis direction are bent in the negative X-axis direction, and tip portions 232 of lead terminals 222 facing the negative Z-axis direction are bent in the positive X-axis direction. In contrast, in even-numbered energy storage elements 21, tip portions 231 of lead terminals 221 facing the positive Z-axis direction are bent in the positive X-axis direction, and tip portions 232 of lead terminals 222 facing the negative Z-axis direction are bent in the negative X-axis direction.

[0045] The lead terminals 220 of each energy storage element 21 are joined to the lead terminals 220 of the other energy storage elements 21 or to a bus bar. Specifically, the lead terminal 221 of the first energy storage element 21 has a tip 231 welded to a bus bar (not shown). The tip 232 of the lead terminal 222 of the first energy storage element 21 and the lead terminal 222 of the second energy storage element 21 are welded to each other. The tip 231 of the lead terminal 221 of the second energy storage element 21 and the lead terminal 221 of the third energy storage element 21 are welded to each other. The tip 232 of the lead terminal 222 of the third energy storage element 21 and the lead terminal 222 of the fourth energy storage element 21 are welded to each other. The tip 231 of the lead terminal 221 of the fourth energy storage element 21 is welded to another bus bar (not shown).

[0046] [Detection Line] Fig. 4 is a plan view showing the energy storage unit 20 according to the embodiment. Specifically, Fig. 4 is a plan view of the energy storage unit 20 as viewed from the negative Y-axis direction. In Fig. 4, the fixing member 40 is indicated by dot hatching. In Fig. 4, the fixing member 40 is illustrated so that the members overlapping the fixing member 40 can be seen through, but the fixing member may be a transparent member or an impermeable member.

[0047] 4, five detection lines 36 are provided. Hereinafter, the first detection line may be referred to as detection line 361, the second detection line 362, the third detection line 363, the fourth detection line 364, and the fifth detection line 365.

[0048] Each detection line 36 is individually supported by a detection line holding member 28 of the second holding member 24. The detection line holding member 28 has a plurality of walls 281 formed thereon to separate each detection line 36. Each wall 281 protrudes in the negative Y-axis direction from the main surface of the detection line holding member 28 and extends in the X-axis direction. The multiple walls 281 are arranged at predetermined intervals in the Z-axis direction. Each wall 281 separates each detection line 361 to 364.

[0049] Each detection wire 36 extends in the negative X-axis direction from the substrate support portion 27 of the second holding member 24 and is bent on the detection wire holding member 28, with each tip 36a extending along the X-axis direction. Specifically, the tip 36a of the detection wires 361, 363, and 365 protrudes in the positive Z-axis direction from the detection wire holding member 28. In contrast, the tip 36a of the detection wires 362 and 364 protrudes in the negative Z-axis direction from the detection wire holding member 28.

[0050] The tip 36a of the detection wire 361 is joined to the tip 231 of the lead terminal 221 of the first energy storage element 21. The tip 36a of the detection wire 362 is joined to the tip 232 of the lead terminal 222 of the first energy storage element 21. The tip 36a of the detection wire 363 is joined to the tip 231 of the lead terminal 221 of the second energy storage element 21. The tip 36a of the detection wire 364 is joined to the tip 232 of the lead terminal 222 of the third energy storage element 21. The tip 36a of the detection wire 365 is joined to the tip 231 of the lead terminal 221 of the fourth energy storage element 21.

[0051] [Fixed part] Next, the fixing member 40 will be described. The fixing member 40 is a sheet member that collectively fixes the lead terminals 222 and the detection wires 36. Specifically, the fixing member 40 is an adhesive tape that is rectangular when viewed in the Y-axis direction. The end of the fixing member 40 in the negative X-axis direction is disposed near the end of the first holding member 23 in the negative X-axis direction. The end of the fixing member 40 in the positive X-axis direction is disposed near the end of the second holding member 24 in the positive X-axis direction. The end of the fixing member 40 in the negative Z-axis direction is disposed between the tip ends 36a of the detection wires 362, 364 and the bus bar support portion 26. The end of the fixing member 40 in the positive Z-axis direction is disposed between the tip ends 231 of the lead terminals 221 and the edge of each energy storage element 21 in the positive Z-axis direction.

[0052] As a result, the fixing member 40 overlaps and is adhered to the small wall 251 of the first holding member 23, the lead terminals 221, 222 of each storage element 21, each detection wire 36, the detection wire holding member 28, and the surrounding wall 29 of the second holding member 24. In this state, the fixing member 40 overlaps and fixes each lead terminal 221, 222 and each detection wire 36, and also fixes each detection wire 36 and the detection wire holding member 28. Furthermore, the fixing member 40 is fixed to the first holding member 23 and the second holding member 24.

[0053] FIG. 5 is a cross-sectional view showing a fixing member 40 according to an embodiment. As shown in FIG. 5, the fixing member 40 includes a first adhesive layer 41, a first base material layer 42, a second adhesive layer 43, and a second base material layer 44. The first adhesive layer 41, the first base material layer 42, the second adhesive layer 43, and the second base material layer 44 are stacked in this order from the side of the objects to be bonded (the first holding member 23, the lead terminals 221 and 222, the detection line 36, the detection line holding member 28, and the second holding member 24). In other words, the second base material layer 44 is disposed farther from the objects to be bonded than the first base material layer 42. The first adhesive layer 41 is a layer made of an adhesive that is bonded to the objects to be bonded. The second adhesive layer 43 is a layer made of an adhesive that bonds the first base material layer 42 and the second base material layer 44 together.

[0054] Here, the surface resistance of the first substrate layer 42 is higher than the surface resistance of the second substrate layer 44. The first substrate layer 42 is formed of a material having a higher surface resistance than the material forming the second substrate layer 44. Furthermore, the tensile strength of the second substrate layer 44 is higher than the tensile strength of the first substrate layer 42. The second substrate layer 44 is formed of a material having a higher tensile strength than the material forming the first substrate layer 42. Specifically, the first substrate layer 42 is formed of resin, and the second substrate layer 44 is formed of glass cloth. The surface resistances of the first substrate layer 42 and the first substrate layer 43 can be measured in accordance with JIS K6911:2006. In other words, the higher the surface resistance, the higher the insulating performance, and the lower the surface resistance, the lower the insulating performance. Furthermore, the tensile strength of the first substrate layer 42 and the first substrate layer 43 can be measured in accordance with JIS K7127:1999.

[0055] [Effects, etc.] As described above, according to the present embodiment, the lead terminals 221, 222 and the detection wire 36 are fixed by the fixing member 40, and therefore, even if the lead terminals 221, 222 vibrate due to vibration of the energy storage element 21, the detection wire 36 follows suit due to the fixation. Furthermore, the lead terminals 221, 222 and the detection wire 36 are overlapped and fixed by the fixing member 40, so the lead terminals 221, 222 and the detection wire 36 can be stably fixed. As a result, load is less likely to be applied to the joints between the lead terminals 221, 222 and the detection wire 36, and damage to the joints can be suppressed.

[0056] Since the detection line 36 is fixed to the detection line holding member 28 by the fixing member 40, the detection line 36 can be held more stably. Therefore, the load on the joint between the lead terminals 221, 222 and the detection line 36 can be further reduced, and damage to the joint can be further reduced.

[0057] Since the fixing member 40 is fixed to the holding member 22 (first holding member 23 and second holding member 24), the fixing member 40 can easily follow the vibrations of the energy storage element 21 and the holding member 22. This makes it possible to suppress displacement of the fixing member 40 due to vibrations, and therefore the lead terminals 221, 222 and the detection line 36 can be stably fixed.

[0058] Because second holding member 24 is provided with detection line holding member 28 continuously, fixing member 40 can easily follow vibrations of energy storage element 21, second holding member 24, and detection line holding member 28. This further reduces positional deviation of fixing member 40 caused by vibration, allowing lead terminals 221, 222 and detection line 36 to be fixed more stably.

[0059] Because the fixing member 40 is an adhesive tape, the detection line 36 can be fixed to the bonding object with a simple configuration. Furthermore, the surface resistance of the first base material layer 42, which is arranged in a position close to the bonding object, is higher than the surface resistance of the second base material layer 44, which reliably improves the insulation performance of the energy storage device 1. In addition, because the tensile strength of the second base material layer 44, which is arranged in a position far from the bonding object, is higher than the tensile strength of the first base material layer 42, it is possible to reliably improve the strength of the energy storage device 1 even in positions far from the bonding object where displacement during vibration becomes large.

[0060] [Description of Modifications] Below, various modified examples of the above embodiment will be described. In the following description, parts that are the same as those in the above embodiment or other modified examples will be given the same reference numerals, and their description may be omitted. The fixing member 40 may be in any form as long as it can fix the lead terminals 221, 222 and the detection line 36 in an overlapping manner. In the following modified examples 1 to 4, other examples of the fixing member 40 will be described.

[0061] (Variation 1) In the first modification, a case will be described in which one fixing member 40a fixes one lead terminal 221, 222 and one detection line 36. That is, the electricity storage unit 20a is provided with a plurality of fixing members 40a.

[0062] FIG. 6 is a plan view showing an energy storage unit 20a according to Modification 1. FIG. 6 is a view corresponding to FIG. 4. As shown in FIG. 6, the tip 36a of the detection wire 361 and the tip 231 of the lead terminal 221 of the first energy storage element 21 are covered and fixed by a single fixing member 40a in an overlapping state. The tip 36a of the detection wire 362 and the tip 232 of the lead terminal 222 of the first energy storage element 21 are covered and fixed by a single fixing member 40a in an overlapping state. The tip 36a of the detection wire 363 and the tip 231 of the lead terminal 221 of the second energy storage element 21 are covered and fixed by a single fixing member 40a in an overlapping state. The tip 36a of the detection wire 364 and the tip 232 of the lead terminal 222 of the third energy storage element 21 are covered and fixed by a single fixing member 40a in an overlapping state. Tip portion 36a of detection wire 365 and tip portion 231 of lead terminal 221 of fourth power storage element 21 are overlapped and covered and fixed by one fixing member 40a.

[0063] According to the first modification, it is possible to achieve the same effects as the above-described embodiment. In particular, in the first modification, since a plurality of fixing members 40a are provided, it is possible to set the surface resistance or tensile strength of each fixing member 40a to be different. Furthermore, it is possible to set the width of each fixing member 40a in the X-axis direction or the Z-axis direction as desired. In other words, it is possible to increase the degree of freedom in designing the fixing members 40a.

[0064] (Variation 2) In the second modification, a case will be described in which one lead terminal 221, 222, one detection line 36, and the detection line holding member 28 are fixed by one fixing member 40b. That is, the power storage unit 20b is provided with a plurality of fixing members 40b.

[0065] Fig. 7 is a plan view showing an energy storage unit 20b according to Modification 2. Fig. 7 is a view corresponding to Fig. 4. As shown in Fig. 7, fixing member 40b, which fixes tip portion 36a of detection wire 361 to tip portion 231 of lead terminal 221 of the first energy storage element 21, fixes tip portion 36a of detection wire 361 and detection wire holding member 28 in an overlapping manner. Fixing member 40b, which fixes tip portion 36a of detection wire 362 to tip portion 232 of lead terminal 222 of the first energy storage element 21, fixes tip portion 36a of detection wire 362 and detection wire holding member 28 in an overlapping manner. Fixing member 40b, which fixes tip portion 36a of detection wire 363 to tip portion 231 of lead terminal 221 of the second energy storage element 21, fixes tip portion 36a of detection wire 363 and detection wire holding member 28 in an overlapping manner. Fixing member 40b, which fixes tip portion 36a of detection wire 364 and tip portion 232 of lead terminal 222 of the third energy storage element 21, overlaps and fixes tip portion 36a of detection wire 364 and detection wire holding member 28. Fixing member 40b, which fixes tip portion 36a of detection wire 365 and tip portion 231 of lead terminal 221 of the fourth energy storage element 21, overlaps and fixes tip portion 36a of detection wire 365 and detection wire holding member 28.

[0066] According to the second modification, it is possible to achieve the same effects as the above-described embodiment. In particular, in the second modification, since a plurality of fixing members 40b are provided, the tip end 36a of the detection line 36 and the detection line holding member 28 can be overlapped and fixed for each fixing member 40b. In other words, by arbitrarily setting the width in the X-axis direction or the width in the Z-axis direction of each fixing member 40b, it is possible to individually change the overlapping area between each fixing member 40b and the detection line holding member 28. This makes it possible to change the degree of reinforcement depending on the location requiring reinforcement. In other words, it is possible to further increase the degree of freedom in designing the fixing members 40b.

[0067] (Variation 3) In the third modification, a case will be described in which two fixing members 40c are provided in the electricity storage unit 20c, and the fixing members 40c are bonded to the detection line 36, the lead terminals 221 and 222, the first holding member 23, and the second holding member 24, respectively.

[0068] Fig. 8 is a plan view showing an electricity storage unit 20c according to Modification 3. Fig. 8 is a view corresponding to Fig. 4. As shown in Fig. 8, the two fixing members 40c are formed to be elongated in the X-axis direction and are arranged side by side in the Z-axis direction.

[0069] Fixing member 40c arranged in the positive direction of the Z axis fixes tip portion 36a of detection wire 361 to tip portion 231 of lead terminal 221 of the first storage element 21, fixes tip portion 36a of detection wire 363 to tip portion 231 of lead terminal 221 of the second storage element 21, and fixes tip portion 36a of detection wire 365 to tip portion 231 of lead terminal 221 of the fourth storage element 21. The end of this fixing member 40c in the negative direction of the X axis is fixed (bonded) to small wall 251 of first holding member 23, and the end in the positive direction of the X axis is fixed (bonded) to surrounding wall 29 of second holding member 24.

[0070] Fixing member 40c, which is arranged in the negative direction of the Z axis, fixes tip 36a of detection wire 362 to tip 232 of lead terminal 222 of the first storage element 21, and fixes tip 36a of detection wire 364 to tip 232 of lead terminal 222 of the third storage element 21. The end of this fixing member 40c in the negative direction of the X axis is fixed (bonded) to small wall 251 of first holding member 23, and the end in the positive direction of the X axis is fixed (bonded) to surrounding wall 29 of second holding member 24.

[0071] According to Modification 3, it is possible to achieve the same effects as the above-described embodiment. In particular, in Modification 3, the tip ends 36a of the detection lines 36 aligned along the X-axis direction can be fixed by fixing members 40c extending along the X-axis direction, making the work of fixing fixing members 40c easy and reliable.

[0072] (Variation 4) In the fourth modification, two fixing members 40d are provided on the power storage unit 20d, and each fixing member 40d is adhered to the detection line 36, the lead terminals 221, 222, the first holding member 23, the second holding member 24, and the detection line holding member 28.

[0073] Fig. 9 is a plan view showing an electricity storage unit 20d according to Modification 4. Fig. 9 is a view corresponding to Fig. 4. As shown in Fig. 9, two fixing members 40d are formed to be elongated in the X-axis direction and are arranged side by side in the Z-axis direction.

[0074] Fixing member 40d arranged in the positive direction of the Z axis fixes tip portion 36a of detection wire 361 to tip portion 231 of lead terminal 221 of the first energy storage element 21, fixes tip portion 36a of detection wire 363 to tip portion 231 of lead terminal 221 of the second energy storage element 21, and fixes tip portion 36a of detection wire 365 to tip portion 231 of lead terminal 221 of the fourth energy storage element 21. The end of fixing member 40d in the negative direction of the X axis is fixed (bonded) to small wall 251 of first holding member 23, and the end of fixing member 40d in the positive direction of the X axis is fixed (bonded) to surrounding wall 29 of second holding member 24. Furthermore, the end of fixing member 40d in the negative direction of the Z axis is fixed (bonded) to detection line holding member 28.

[0075] Fixing member 40d, which is arranged in the negative Z-axis direction, fixes tip 36a of detection wire 362 to tip 232 of lead terminal 222 of the first energy storage element 21, and fixes tip 36a of detection wire 364 to tip 232 of lead terminal 222 of the third energy storage element 21. The end of fixing member 40d in the negative X-axis direction is fixed (bonded) to small wall 251 of first holding member 23, and the end of fixing member 40d in the positive X-axis direction is fixed (bonded) to surrounding wall 29 of second holding member 24. Furthermore, the end of fixing member 40d in the positive Z-axis direction is fixed (bonded) to detection line holding member 28.

[0076] According to the fourth modification, it is possible to achieve the same effects as the above-described embodiment. In particular, in the fourth modification, the tip ends 36a of the detection lines 36 aligned along the X-axis direction can be fixed by the fixing member 40d extending along the X-axis direction, which makes the work of fixing the fixing member 40d easy and reliable. Furthermore, the fixing member 40d is fixed to the first holding member 23 and the second holding member 24, and is also fixed to the detection line holding member 28. In this way, since multiple parts are fixed by a single fixing member 40d, it is possible to suppress positional displacement of the fixing member 40d caused by vibration. In other words, the fixing member 40d makes the work of fixing easy and reliable, and it is possible to suppress positional displacement of the fixing member 40d.

[0077] (others) Although the energy storage device 1 according to the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment. In other words, the embodiment disclosed herein is illustrative in all respects and is not restrictive, and the scope of the present invention includes all modifications within the meaning and scope of the claims.

[0078] In the above embodiment, the exterior film 210 has a rectangular shape when viewed from the X-axis direction, but the exterior film 210 may have any shape. Other shapes of the exterior film 210 include polygonal shapes other than rectangular, oval shapes, elliptical shapes, and circles.

[0079] In the above embodiment, the fixing member 40 includes the first adhesive layer 41, the first base material layer 42, the second adhesive layer 43, and the second base material layer 44. However, the fixing member 40 does not have to include the second adhesive layer 43 and the second base material layer 44. Furthermore, the surface resistance of the first base material layer 42 may be the same as or lower than the surface resistance of the second base material layer 44. The tensile strength of the second base material layer 44 may be the same as or lower than the tensile strength of the first base material layer 42.

[0080] In the above embodiment, the fixing member 40 is an adhesive tape. However, the fixing member 40 may take any form as long as it can overlap and fix the lead terminals 221, 222 and the detection line 36. Other examples of the fixing member 40 include an adhesive.

[0081] In the above embodiment, the case where the second holding member 24 is continuously provided with the detection line holding member 28 has been exemplified. However, the first holding member 23 may be continuously provided with the detection line holding member 28. Furthermore, the detection line holding member 28 may be separate from the first holding member 23 and the second holding member 24. Moreover, the first holding member 23 and the second holding member 24 may be omitted, and the detection line holding member 28 may be omitted.

[0082] In the above embodiment, the lead terminal 220 is bent near the first side 214 of the packaging film 210. However, the lead terminal 220 does not have to be bent. In other words, the lead terminal 220 may extend from the first side 214 of the packaging film 210 in the negative Y-axis direction.

[0083] In the above embodiment, an example is given of a pair of lead terminals 220 protruding from the first side 214 of the exterior film 210, but one of the pair of lead terminals 220 may protrude from the first side 214 of the exterior film 210, and the other lead terminal 220 may protrude from a side other than the first side 214 of the exterior film 210.

[0084] Any combination of the components included in the embodiments and their modifications is also included within the scope of the present invention. [Industrial Applicability]

[0085] The present invention can be applied to an electricity storage device or the like that includes an electricity storage element such as a lithium ion secondary battery. [Explanation of symbols]

[0086] 1. Energy storage device 10. Exterior body 11. Exterior body 12 Exterior body lid 20, 20a, 20b, 20c, 20d Energy storage units 21 Energy storage element 22 Retaining member 23 First retaining member 24 Second holding member 25 Flat plate part 26 Busbar support 27 Substrate support 28 Detection line holding member 29 Enclosure Wall 35 Circuit Board 36, 361, 362, 363, 364, 365 detection lines 36a Tip 40, 40a, 40b, 40c, 40d Fixing members 41 First adhesive layer 42 First base layer 43 Second adhesive layer 44 Second base layer 81 External terminal 111 Aperture 210 Exterior film 211 Electrode body 212 Main body film 213 Frame 214 First Side 220, 221, 222 Lead terminals (terminals) 230, 231, 232 Tip 251 Small wall 281 Wall

Claims

1. a storage element having a terminal; a detection line connected to the terminal for detecting a state of the storage element; a fixing member that fixes the terminal and the detection line in an overlapping manner; Energy storage device.

2. a detection line holding member for holding the detection line; the fixing member fixes the detection line and the detection line holding member; The power storage device according to claim 1 .

3. a holding member for holding the energy storage element, The fixing member is fixed to the holding member. The electricity storage device according to claim 1 or 2.

4. a detection line holding member for holding the detection line; the fixing member fixes the detection line and the detection line holding member; the holding member includes the detection line holding member continuously; The power storage device according to claim 3 .

5. the fixing member is an adhesive tape, the adhesive tape includes a first base material layer and a second base material layer disposed at a position farther from the terminal and the detection line than the first base material layer, the surface resistance of the first base material layer is higher than the surface resistance of the second base material layer; The tensile strength of the second base material layer is higher than the tensile strength of the first base material layer. The electricity storage device according to claim 1 or 2.

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